hamming_decoder_pre

library ieee;
use     ieee.std_logic_1164.all;
use     ieee.std_logic_arith.all;
use     ieee.std_logic_misc.all;
use     ieee.std_logic_unsigned.all;

-- Uncomment the following library declaration if using
-- arithmetic functions with Signed or Unsigned values
--use IEEE.NUMERIC_STD.ALL;

-- Uncomment the following library declaration if instantiating
-- any Xilinx leaf cells in this code.
--library UNISIM;
--use UNISIM.VComponents.all;

entity hamming_decoder is
    Port (
        clk_i : in  std_logic;
        rst_i : in  std_logic;

        -- inputs
        dat_i : in  std_logic_vector(15 downto 0);
        vld_i : in  std_logic;
        rdy_o : out std_logic;

        -- outputs
        dat_o : out std_logic_vector(15 downto 0);
        vld_o : out std_logic;
        rdy_i : in  std_logic
    );

end hamming_decoder;

architecture Behavioral of hamming_decoder is

--HAMMING

--CONSTANT
    constant MAX_COUNT : integer := 1;

--RECEIVE SIG
    signal data_buf   : std_logic_vector (31 downto 0);
    signal count_data : integer range 0  to MAX_COUNT;
--TRANSMIT SIG
    signal buf_zero   : std_logic_vector (15 downto 0);

--TYPE
    type   decoder_type is (RECEIVE_DATA, DECRYPTION, SENDING_DATA);
    signal decoder_state: decoder_type;

begin

    RECEIVE_PROC : process (clk_i, rst_i)
    begin
        if rst_i = '1' then
            data_buf <= (others =>'0');
            decoder_state <= RECEIVE_DATA;
            rdy_o <= '0';
            dat_o <= (others =>'0');
            vld_o <= '0';
            buf_zero <= (others =>'0');
        elsif rising_edge(clk_i) then
            case decoder_state is
                when RECEIVE_DATA =>
                rdy_o <= '1';
                    if vld_i = '1' then
                        data_buf <= data_buf(15 downto 0) & dat_i;
                        if count_data = MAX_COUNT then
                            count_data <= 0;
                            decoder_state <= DECRYPTION;
                            rdy_o <= '0';
                        else
                            count_data <= count_data + 1;
                        end if;
                    end if;

                when DECRYPTION =>
                    decoder_state <= SENDING_DATA;

                when SENDING_DATA =>
                    vld_o <= '1';
                    if rdy_i = '1' then
                        data_buf <= data_buf(15 downto 0) & buf_zero;
                        dat_o <= data_buf(31 downto 16);
                        if count_data = MAX_COUNT then
                            count_data <= 0;
                            decoder_state <= RECEIVE_DATA;
                            rdy_o <= '0';
                            vld_o <= '0';
                        else
                            count_data <= count_data + 1;
                        end if;
                    end if;
            end case;
        end if;
    end process;
end Behavioral;